refactor: extract magic values into named constant modules

Scattered numeric literals had no names at their use sites, making it
impossible to know whether two identical values were intentionally the
same or coincidentally equal. Moving them to typed constants makes the
relationship explicit and ensures a single edit propagates everywhere.

src/main/constants/input.ts

@@ -0,0 +1,3 @@
+export const TRIGGER_THRESHOLD = 8
+export const DEDUP_WINDOW_MS = 40
+export const HOTPLUG_SCAN_INTERVAL_MS = 3_000

src/main/input/gamepadReader.ts

@@ -32,6 +32,7 @@
 import * as fs from 'node:fs'
 import * as path from 'node:path'
 import type { BrowserWindow } from 'electron'
+import { DEDUP_WINDOW_MS, HOTPLUG_SCAN_INTERVAL_MS, TRIGGER_THRESHOLD } from '../constants/input'
 
 // evdev input_event auf 64-bit Linux:
 // { u64 tv_sec (8 Bytes), u64 tv_usec (8 Bytes), u16 type (2), u16 code (2), s32 value (4) } = 24 Bytes
@@ -70,16 +71,10 @@ const BUTTON_MAP: Record<number, string> = {
 }
 
 const STICK_THRESHOLD = 16384  // ~50% von 32767
-// Trigger-Schwellwert: Achsenwert > 0 (nicht gedrückt) bis ~255–1023 je Controller
-const TRIGGER_THRESHOLD = 8
 const REPEAT_INITIAL_MS = 400
 const REPEAT_INTERVAL_MS = 150
 // Trigger-Achsen sollen kein Auto-Repeat auslösen (300s-Sprünge nicht wiederholen)
 const NO_REPEAT_ABS_CODES = new Set([ABS_Z, ABS_RZ])
-const SCAN_INTERVAL_MS = 3000
-// Bluetooth-/Steam-Setups können dieselbe Eingabe über mehrere Devices liefern.
-// Nahezu zeitgleiche identische Events werden global entdoppelt.
-const DUPLICATE_EVENT_WINDOW_MS = 40
 
 interface AxisState {
   key: string | null
@@ -367,7 +362,7 @@ export function startGamepadReader(getWindow: () => BrowserWindow | null): () =>
   const onKey = (key: string): void => {
     const now = Date.now()
     const lastAt = lastKeyAt.get(key) ?? 0
-    if (now - lastAt < DUPLICATE_EVENT_WINDOW_MS) return
+    if (now - lastAt < DEDUP_WINDOW_MS) return
     lastKeyAt.set(key, now)
 
     const win = getWindow()
@@ -427,7 +422,7 @@ export function startGamepadReader(getWindow: () => BrowserWindow | null): () =>
   }
 
   scanDevices()
-  const timer = setInterval(scanDevices, SCAN_INTERVAL_MS)
+  const timer = setInterval(scanDevices, HOTPLUG_SCAN_INTERVAL_MS)
 
   return () => {
     clearInterval(timer)